The present invention relates to a thermal ink transfer printing and recording apparatus of the nonimpact type.
With the thermal ink transfer printing apparatus, an ink carrying film whose ink is softened or melted by heating is joined with a recording sheet and heat is applied to a predetermined picture region so that the softened or melted ink may be transferred to the recording sheet. The printing apparatus of this type is so simple in principle and configuration as to be easily inspected.
FIG. 1 shows a conventional thermal ink transfer printing apparatus of the serial type cited from Japanese Patent Publication No. 21471/Sho-57, for example. With this thermal ink transfer printing apparatus, reels 14 and 16 for supplying and winding an ink film 12 are arranged on a carriage 10, and the ink ribbon 12 fed from the reel 14 is wound by the reel 16 through a thermal head 18 where a heating resistance is formed. The carriage 10 reciprocates in a direction perpendicular to the moving direction of a recording sheet 20. During the reciprocating movement of the carriage 10, the ink film 12 is put on the recording sheet 20 in such a way that they do not move relative to each other, and the thermal head 18 generates heat selectively responsive to recording signal. Ink softened and melted by the heat selectively generated from the thermal head 18 is transferred to the recording sheet 20.
With this conventional thermal ink transfer printing apparatus, however, the ink film 12 is being wound by the reel 16 even when the carriage 10 runs at the blank portion of the recording sheet where no picture is to be recorded. The ink film 12 is therefore wasted in vain, leaving that portion thereof unused which is not heated by the thermal head 18 and is not transferred to the recording sheet. As apparent from the above, the conventional thermal ink transfer printing apparatus is low in the efficiency of using the ink film.
In addition, as the diameter of the ink film wound by the reel 16 becomes larger and larger, the angle formed by the running passage of the ink film 12 and the thermal head 18 changes to thereby vary the force by which the ink film 12 is urged to the thermal head 18. Unevenness is thus caused in the consistency of ink transferred by the thermal head, and ink transfer capacity is made worse particularly when the diameter of the ink film wound around the reel 16 becomes large. Further, in the case of this reel 16 which is rotated to wind the ink film, the relationship between the rotating speed of said reel 16 and the running speed of the ink film 12 is changed by the diameter of the ink film wound around the reel 16. In order to run the ink film 12 at a certain speed, therefore, the rotating speed of the reel 16 must be changed corresponding to the diameter change of the ink film wound around the reel 16. No conventional thermal ink transfer recording apparatus, however, could eliminate the above-mentioned drawbacks by means of a simple mechanism.